import java.util.Scanner;


public class Calc {
	private static Scanner scn;

	public static void main(String[] args) {
	        String vir;
	        int s = 0;
	        int i = 0;
	        double ch1 = 0;
	        double ch2 = 0;
	        
	        scn = new Scanner(System.in);
	        System.out.print("Vvedite virazhenie ");
	        vir = scn.nextLine();
	        vir = vir.replaceAll(" ", "");
	        
	        for (int j = 0; j < vir.length(); j++) {
	                if (vir.charAt(j) == '+' | vir.charAt(j) == '-' | vir.charAt(j) == '/' | vir.charAt(j) == '*') {
	                        if (s == 0) {
	                                ch1 = Double.parseDouble(vir.substring(0, j));
	                                i = j;
	                        }
	                        else if (s == 1){
	                                ch2 = Double.parseDouble(vir.substring(j, vir.length()));
	                        }
	                        else if (s > 1) {
	                                System.out.println("Chisel bolshe, chem 2");
	                                return;
	                        }
	                        s++;
	                }       
	        }
	        if (s == 0) {
	                System.out.println("Proverte pravilnost' zapici");
	                return;
	        }

	        char operation = vir.charAt(i);
	        switch (operation) {
	        
	        case '+':
	                System.out.println(ch1 + ch2);
	                break;
	                
	        case '-':
	                System.out.println(ch1 - ch2);
	                break;
	                
	        case '/':
	                System.out.println(ch1 / ch2);
	                break;
	                
	        case '*':
	                System.out.println(ch1 * ch2);
	                break;
	                
	        default:
	                System.out.println("Proverte pravilnost' zapici");
	                break;
	                
	        }

	}

	}